Let b= length and a=width
Area= a*b and the problem said b=2a+3 (the length is 3ft more than double the width)
Replace b into Area formula:
Area= a*(2a+3) and we know that Area=77ft from the problem, so:
77=2a^2+3a now order and equal to zero:
2a^2+3a=77 now solve this with quadratic formula and you will get so values for a: -7ft and 5.5ft as you know the dimensions could not be negative so the correct answer for "a" side is 5.5ft, for getting the b side you haeve to replace a=5.5 into b=2a+3 and you will get b=2*5.5+3= 14ft.
Finished.
